1. Field of the Invention
The present invention relates to a fin structure for heat-exchanging which is mounted on an heat dissipating or absorbing portion of a Stirling cycle cooler.
2. Description of the Related Art
Recently, a refrigerating container using a Stirling cycle cooler has been extensively used as a CFC (chlorofluorocarbon) substitute refrigerating apparatus. The Stirling cycle cooler is a closed cycle engine which absorbs and dissipates heat by expanding and compressing a working gas with a piston driven by an external power and a displacer reciprocated at a predetermined phase difference relative to the piston, and repeating these processes. A cooling portion thereof is thermally connected to the refrigerating container via a heat-exchanger for heat-absorbing, while a cooling of the refrigerating container is carried out by this heat-exchanger. In a heat-dissipating portion of the Stirling cycle cooler, since an interior thereof is brought into a high-temperature state, a fin structure as a heat-exchanger for heat-dissipating portion is mounted on an outer circumference of the heat-dissipating portion. By sending air to the fin structure, the temperature of the heat-dissipating portion is lowered.
For instance, Japanese Unexamined Patent Publication No. 2002-62021 discloses a conventional fin assembly. As shown in FIG. 5, the conventional fin structure 101 is mounted on the Stirling cycle cooler 100. The fin structure 101 has fins 103 provided on an outer circumference of an annular holding rim 102, wherein the fins 103 are formed by folding a plate material of a predetermined length perpendicularly relative to a longitudinal axial line thereof at essentially equal intervals, while the fin structure 101 is formed in an annular shape as a whole. The Stirling cycle cooler 100 is inserted into the fin structure 101 along a central axis thereof to reach a heat-dissipating portion 104, whereby the fin structure 101 is mounted on the Stirling cycle cooler 100. Meanwhile, the holding rim 102 of the fin structure 101 is thermally bonded to the heat-dissipating portion 104 of the Stirling cycle cooler 100 with a thermally conductive adhesive, filler, solder, or the like.
The fin structure 101, however, has problems that, when inserting the Stirling cycle cooler 100, the thermally conductive adhesive, filler or the like adheres to an upper portion of the Stirling cycle cooler 100, so that the upper portion becomes dirty, and the applied condition of the thermally conductive adhesive or the like in an inner circumference of the holding rim 102 becomes non-uniform due to adhesion of the thermally conductive adhesive or the like on the upper portion of the Stirling cycle cooler 100. Moreover, in the case that the fin structure 101 is pressed into the Stirling cycle cooler 100 by pushing it from the above of the Stirling cycle cooler 100, considerable force is necessary, and thus mounting the fin structure 101 is not easy. In addition, a casing of the Stirling cycle cooler 100 may be scratched and distorted when pressing the fin structure 101, and in the worst case, the casing may be broken due to an excessive external force applied thereto. Further, in the case that the fin structure 101 is fixed to the Stirling cycle cooler 100 by the solder or the like, the casing may be distorted since the casing is partially brought into a high-temperature state due to the melting of the solder or the like.